1. Field of the Invention
The field of the invention is that of solid lasers. More specifically, the invention relates to a laser device that is monolithically integrated with a generator of optic frequencies different from the emission frequency of the laser.
The invention thus enables, for example, an increase in the optic frequency of the laser radiation and, hence, a reduction in the corresponding wavelength. It can therefore be applied, in particular, to cases where the definition capacity of the system including the laser is a function of a wavelength and, for example to digital optic disk readers wherein the storage density is inversely proportional to the square of the wavelength.
The invention also enables the making of tunable frequency laser devices.
A great many other applications are possible according to the principle of the invention, as will be perceived by those skilled in the art.
2. Description of the Prior Art
There is a known way of making waveguides out of optic materials. A waveguide of this kind can be obtained, for example, by titanium diffusion or proton exchange.
The waveguide thus obtained has a refractive index n.sub.1 higher than the index n.sub.2 of the crystal. Since its section has a very small area, of the order of some .mu.m.sup.2, a waveguide such as this can be used to obtain a very high power density and hence a strong electric field.
Furthermore, there are several known ways of making waveguides by which the frequency of an optic wave can be doubled, by using nonlinear optic materials of the lithium niobate LiNbO.sub.3 type.
To obtain a laser radiation at a frequency different from the emission frequency, it has been necessary up till now to have available, firstly, a laser and, secondly, a waveguide made of a nonlinear optic material and prepared with a view to a frequency change. The connection between these elements, firstly, causes, firstly, optic losses and, secondly, results in a relatively bulky device.